Chopping the straw did not affect (P>.05) any of the
investigated parameters. Mean straw intake was 2.36 kg DM/d,
which represented 84.1 % of the total DM intake. The camels spent
39 % of their time ruminating, 29 % eating and 32 % resting.
About 97 % of the eating activity occured during daytime versus
44.4 % for ruminating and 45 % for resting.

It was concluded from comparison of these results with
literature data on cattle and sheep that camel did not appear to
digest more extensively poor quality roughages.

Key words: Camel, straw, intake, digestion, feeding
behaviour

Introduction

One-humped camel (Camelus dromedarius) thrives in an
arid environment where the supply of good quality forages is very
limited. Its selective retention of feed particles in the
fermentation chambers (Heller et al 1986) may be one of
the many factors responsible for its adaptation to low quality
feeds. Retention in the gut is related to the size of offered
forage particles, and to eating and ruminating behaviour.

In this study, intake, digestion and feeding behaviour of the
camel fed long or chopped straw-based diets where investigated.

Materials and methods

In this experiment which began in March 1989, four 200 kg
one-humped camels aged about 16 months were housed in an open
barn on concrete floors and confined by tying one of their
anterior feet to the wall. During an 8 week period of adaptation
they were offered wheat straw ad libitum supplemented with
0.5 kg of a concentrate based on barley. At the same time, the
camels were accustomed to the presence of the researchers, to
fecal collecting harnesses and to the ingestive behaviour
recording clock.

Following this adaptation period, the camels were used in a 2
x 2 Latin Square replicated twice. The treatments were wheat
straw in the long form with an average length of 15 cm, and
chopped wheat straw with an average length of 8.5 cm. Thus, in
each experimental period, two camels received the long straw
while the others received the chopped one.

Each of the two experimental periods consisted of a 10-day
preliminary period and a 9-day period for fecal collection and
eating behaviour recording. During the experimental periods,
sufficient straw was offered twice daily at 08.00 and 14.00
hours.

A restricted quantities (0.5 kg/d) as fed of a concentrate
made of wheat bran, urea and mineral supplement was given at
14.00 hours in one of two feeders for each camel. The chemical
analysis of the concentrate as given in table 1. The amount of
concentrate was restricted to give a diet containing about 80 %
straw similar to one which might ensure maintenance nutrient
intake. The camels had access to their assigned diets and water
at all times.

Measurements of time spent eating, ruminating and resting were
made with a vibracorder (Ruckebush and Bueno 1973) for two
periods of 24 h. For measurements of digestibility, total fecal
collections were made twice or three times a day in collection
bags made of cloth (outside) and plastic (inside).

The concentrate and offered and refused straw, which were
collected and weighed before each morning meal, were sampled
daily for DM determination and subsequent chemical analyses.
Feces were dried at 80 °C and sampled
for chemical analyses.

The chemical analyses of feeds, refusals and feces were made
by standard procedures on dried materials.

Statistical analyses were conducted according to procedures
for repeated (multiple) Latin Square design.

Results and discussion

The daily total DM intakes (DMI) were relatively low: 2.73 to
2.88 kg (table 2). Nitrogen intake might have limited DMI since
calculated crude protein contents of the diets were only 6.0 %
and 6.2 % of DM. Furthermore, it should be recognized that the
animals were young which might have affected voluntary intake;
using older camels could have led to higher intake as reported by
Farid et al (1980) when camels weighing 538 kg ate 3.6 kg
of a diet made of straw and legume hay. Maloiy (1972) found daily
intakes by stall-fed camels averaging between 190 and 460 kg
varying from 1.3 to 5.3 kg DM of poor chopped hay from a mixed
pasture containing mainly star grass (Cynodon dactylon).
The chemical composition of straw offered and refused (table 2)
shows that the camels selected the more nutritive parts of the
straw. They seemed to prefer more nitrogen-rich parts. Such
behaviour has been reported for camels on pasture by Maloiy
(1972) who indicated that plants selected by camels had high
water and protein contents.

Unexpectedly, chopping the straw tended to decrease its
voluntary intake. Straw intakes by camels found in this study are
intermediate between those reported for sheep (Abdouli et al
1988; Xande 1978) and cattle (Hoden 1972, Abdouli et al 1988).
Parameters and patterns of feeding behaviour are shown in tables
3 and 4. The camels spent about 40 % of their time ruminating and
30 % for eating or resting. Sunrise initiated eating which was
intensified following meal distribution and ceased shortly after
sunset. Thus while eating occured mainly during the day,
ruminating and resting were almost equally partitioned between
the day and the night.

Table 3: Total
intake and parameters of the feeding behaviour of camels
fed straw ad libitum

Chopping the straw did not modify significantly (P>.05)
feeding parameters nor pattern; only slightly shorter ruminating
and longer resting times were associated with the chopped straw.
Also a small decrease in eating rate (voluntary intake in g DM/d
divided by eating time in h/d) due to a reduced intake was
observed and indicated that the camels might have had more
ability to select through chopped straw.

Table 4: Partition
of feeding activities in camels fed straw ad libitum (%
of time of each activity)

No reports on ingestive behaviour and related activities in
camels are available to us, and only indirect comparison with
other domestic ruminants can be made. It has been reported
(Thomas and Campling 1977) that stall-fed sheep and cows offered
long grass hay ad libitum, ate for 373 and 324 min/d,
respectively, which are shorter times than the 423 min/d spent by
the camels; the ruminating times were, however, similar for sheep
(540 min/d), cows (542 min/d) and camels (542 and 580 min/d). The
eating rate and the ruminating efficiency (voluntary intake, in g
DM/d divided by ruminating time, in h/d) for the camels are about
two times higher than those for sheep (185 and 128 g DM/h for
eating rate and ruminating efficiency, respectively) and 4 to 5
times shorter than those for cows (2088 and 1248 g DM/h for
eating rate and ruminating efficiency, respectively). This does
not necessarily imply that camels chew feed finer than do cows
since feed particles as large as 3 cm have been found in the
intestine of camels (Heller et al 1986); whereas for
bovines, particles larger than 1 mm do not pass through the
omasum. On anatomical grounds, the omasum of the camel is known
to lack the well developped and juxtaposed leaves that screen
coarse particles (Abdouli H unpublished).

Coefficients of apparent digestion of the diets are presented
in table 5. They show that only crude fiber digestibility (CFD)
was somewhat high. When the contribution of the concentrate was
removed assuming its CFD was 30 % (Demarquilly et al
1978), then the digestibilities of the straw CF were 67.3 and
63.5 % for long and chopped straw, respectively.

Chopping the straw did not affect (P>.05) the digestibility
of DM, OM and CF. This is in agreement with the similarity of the
total intakes, and the feeding behaviour associated with the two
forms.

When coefficients of digestion for camels were compared with
corresponding values for sheep and cattle, camels did not appear
more efficient in digesting DM, OM or CF of poor quality roughage
diets. Thus, Abdouli et al (1988) reported DM
digestibility of 60.7 % for sheep offered long straw ad
libitum with 200 g barley- based concentrate; the
digestibility of straw CF being 65.1 %. In a compartive study,
Maloiy (1972) found that Zebu steers digested hay better than
camels; the DM digestibilities were: 64 vs 50 %. Thomas
and Campling (1977) reported digestibilities of 69.0 and 69.7 %
for cellulose of hay offered to sheep and cows, respectively.

It is concluded that although the camels spent a large part of
their time eating, they had limited intakes of straw. Their
ruminating efficiency was low but this did not seem to give them
advantage over other domestic ruminants to digest better fibrous
materials. Chopping the straw did not affect the apparent
digestibility, not did it modify the feeding behaviour. However,
the low nitrogen intake might have masked the ability of the
camel to consume a larger quantity of straw, and to digest it
extensively.

Acknowledgements

The authors are grateful to Dr C Kayouli for providing the
vibracorder clock, and to Mr R Sansoucy for reviewing the
manuscript.